Stoker conveyer



y w. o. MARTIN STOKER CONVEYER Filed Sept. 12, 1940 Patented July 6, 1943 ENE OFFICE STOKER CONVEYER Application September 12, 1940, Serial No. 356,493

4 Claims.

The invention relates to a conveyer more especially applicable to locomotive stokers involving a substantially horizontal conveying conduit provided with a conveyer screw whereby the fuel is transmitted from the coal bin of the tender, or other source of supply, forwardly and discharged through a riser portion of the conduit of crosssectional configuration differing from that of the screw containing portion of the conduit and which may be disposed upwardly at any angle to the horizontal screw containing portion of the conduit.

My invention contemplates a circumferential continuous floating conveyer or tube having a tiltable mounting on the engine frame adapted to prevent in and out or longitudinal movement of the conduit while compensating for differences in expansion and contraction between the firebox and engine frame and permitting lateral movement of the conduit.

The invention also contemplates a conduit without obstructions throughout its length, namely forward of the fuel receiving and breaking section of the stoker, in which the conveyer screw rests on the bottom of the conduit and hence the conduit is free of screw-shaft bearings; a conduit provided with a 'yieldable end wall or closure, normally maintained in closed position by regulable means, adapted to relieve any undue pressure; and furthermore a conduit provided with a riser portion or section communicating and integrally connected with the top of the conduit rearward of its forward end and of different crosssectional configuration which prevents packing and undue frictional and pulverizing action and enables the fuel or coal to be delivered in a loose mass and hence enables a more uniform introduction into the firebox.

My invention also contemplates a continuous screw shaft with the screw flights approximating the inner diameter of the conduit and. of the same diameter throughout; the flights being in the same direction from the receiving end of the conduit to a point adjacent th forward wall of the riser portion of the conduit at which point the flights of the conveyor screw are reversed; with the forward feeding flight of the screw at a point beneath the riser portion of the conduit olfset, radially, on the shaft relative to the main portion of the forward flights and to the reverse flights, thereby neutralizing the thrusts on the screw-shaft in its upward deflection of the coal and permitting the use of a materially lighter conveying system to be employed than has heretofore been possible.

The foregoing enumerated objects and advantages, as well as other advantages in the invention, will all be readily comprehended from the detailed description of the accompanying drawing wherein:

Figure 1 is a, vertical longitudinal sectional view of the forward portion of my improved conveyer shown in conjunction with portions of the back wall of a locomotive firebox and of the engine frame.

Figure 2 is a longitudinal sectional view taken substantially on the line 2-2 of Figure 1 Figure 3' is a sectional end elevation taken on the oifset line 3-3 of Figure 2.

Figure 4 is a detail cross sectional view on a reduced scale of a portion of the engine frame illustrating method of supporting the conduit.

My improved conveyer mechanism, while applicable for other uses, is more especially intended for locomotive stokers whereby the fuel is delivered from a substantially horizontal conduit upwardly into the firebox of the locomotive, as for example through the firing opening in the backhead of the boiler shown at Ill.

The conveyer mechanism involves a substantially horizontally disposed cylindrically con-- tinuous tube or conduit I I provided in its top and at a predetermined distance removed from its forward end with an opening which is provided with a riser l2 of rectangular cross-section and of increasing dimensions toward its upper end where it is shown extending slightly through an opening in the bottom of an enlarged hood or receptacle [3 which is shown disposed about the firing opening in the rear wall of the firebox; the riser l2 preferably being of greater dimensions in a direction transversely of the firebox than in a direction lengthwise of the stoker mechanism. With my improved riser, the coal, deflected upwardly through the opening in the top of the cylindrical conduit ll, separates into a loose mass by reason of the configuration and increased cross-sectional area and is subjected to less friction and pulverization than is the case with constructions as heretofore employed.

The riser I2, preferably by means of a suitable flange I4, is secured to the bottom of the hood l3 secured about the firing opening inthe rear wall of the firebox and extends a short distance above the bottom of the hood, terminating in the horizontal plane of the top of the distributing plate [5 as shown in Figure 1. The riser 12 may extend upwardly from the horizontal conveyer conduit II at any angle in keeping with condithus accommodating the conveyer conduit to slightly varying conditions and to the relative movements between the engine frame and the firebox of the locomotive.

The opening in the top of the conveyer conduit H is at a predetermined distance removed from the forward end of the conduit as shown in Figure 1, namely a distance sufficient to receive the reverse flights of the conveyer screw later to be described.

The forward end of the conduit H is provided with a pressure relieving yieldable end wall or cap 2|. The closure member or end wall 21 is shown with ears 22, 22 at diametrically opposite points and apertured to receive the bolts or pins 23 which extend through registering apertures in a pair of lugs 24 formed at diametrically opposite points on the conduit l I at points slightly removed from the immediate end of the conduit.

The pins 23 have heads at one end and screw threads at the other to receive the washers 25 and nuts 26; the pins preferably also being provided with the Washers 2? which rest against the rear sides of the lugs 26; while the portions of the pins intermediate of the washers or followers 25, 21 are provided with coil springs 28.

As is apparent from the construction disclosed, the tension of springs 28 may be regulated by nuts 26 in keeping with a predetermined normal forward pressure within the conduit; while on the other hand, in th event of excess pressure, the closure member or cap 2| will be forced forwardly from the end of the conduit a distance sufiicient to relieve such excess pressure and prevent damage to the normally closed end of the conduit or to the horizontal conveyer shaft within the conduit; the closure member or cap 21 immediately returning to its seat when the pressure is relieved.

While other methods of yieldingly mounting is shown at 29 in Figure l and in the miniature sectional view Figure 4 so as to compensate for relative movements between the engine-frame and the firebox. This floating or yieldable connection consists of a plate or waist-sheet SE suitably secured to the engine frame 29 so as to extend transversely of the conduit H; the upper edge of the sheet being cut out and a piece of pipe 36* welded thereto, the pipe being bent arcuately in conformance with the curvature of the conduit and the conduit H resting in the arouate socket thus permitting relative transverse or lateral movement between conduit and engine frame. In order, however, to prevent improper in-and-out or longitudinal movement of the conduit, the latter is provided with a pair of angle bars 3|, 2! spaced apart to receive the upper arcuately socketed end of the waist-sheet 3-0, 3%.

The conduit is provided with a conveyer-shaft 32 extending from the driven end (not shown) forward past the riser opening in the conduit and terminating at short distance from the end cap or closure member 2| of the conduit; the conveyer shaft being supported by its screwflights on the bottom of the conduit and providing a conduit without obstructions throughout its length.

The conveyer-shaft 32 is preferably of tubular construction with the flights 33 welded or otherwise suitably secured thereto; the flights of forward movement being shown single, while a short portion of the shaft adjacent to the riser opening in the conduit is preferably provided with double or more flights as shown at 34. The single flights 33 extend to a point approximately a half flight, more or less, rearward of the rear wall of the riser conduit l2, where the flights become double, or more, as at 35 to a line substantially parallel with the rear wall of the riser conduit, at which point the conveyer is provided with one or more flights at 35, which extend to a line parallel, more or less, with the forward wall of the riser conduit, where one or more flights, but of reverse pitch, are employed, as shown at 35. The ends of the forwardly conveying flights 35 are shown radially offset on the shaft relative to the adjacent ends of the forward multiple flights 3-! and the reverse flight 36; the flight 35 in the exempliflcation being shown offset radially approximately ninety degrees. All of the flights are of the same diameter and support the screwshaft on the bottom of the conduit; the shaft 32 coincident with the spherical joints in the conduit H being provided with universal connections as shown at 37; and for convenience in manufacture, the single flight section 35 and the reverse flight section 38 are preferably formed on or secured to a short shaft ection 38, the rear end whereof is snugly inserted in the main tubular shaft 32 at the point 39, Figure 1.

With the conveyer formed as described, namely with the multiple flights 36 and 38, respectively, terminating substantially parallel with the rear and forward walls of the riser conduit l2 and the intermediate flight 35 off-set radially relative to the multiple flights, packing of the coal between the forward and reverse flights is prevented and the necessity of a sloping obstruction or restriction in the conduit beneath the opening to the riser conduit, requiring a horizontally split conduit for introduction of the conveyor screw, is eliminated; thus permitting the use of a nonsplit unobstructed tubular conduit in which the screw-shaft is without bearings and is supported by the screw-flights on the bottom of the conduit and a conveying system with less back pressure between the ends of the multiple flights of the conveyer screw, by reason of the intermediate interruption of the forward feed, is provided.

My improved conveyer system, by reason of its construction, requires less power in operation and permits the use of a tubular screw shaft with the screw flights applied thereto and consequently provides a conveyer of materially less weight than is the case with stoker conveyers as heretofore constructed. At the same time, by having the forward feeding and reverse flights of the conveyer screw terminating, respectively, in lines r substantially parallel with the back wall and the forward wall of the outlet or riser conduit portion and with the intermediate flight arranged offcenter, relative to the other flights, packing of the coal between the forward and reverse flights is prevented and the necessity of employing a split conduit with a deflecting restriction therein adjacent the outlet is eliminated. With my improved conveyer, in the event of leakage of coal past the flights, or because of improper reversing of the screw, packing of coal between the end of the conveyer screw and forward wall of the conduit and causing damage to the conveyer system will be prevented by the pressure relieving end closure member which allows the coal at the end of the conveyer to escape when the pressure reaches a predetermined degree.

The exemplification of the invention has been described in terms employed for purposes of description. and not for limitation as structural modifications are possible and may be made without, however, departing from the spirit of my invention.

What I claim is:

l. A conveyer of the character described comprising a horizontally disposed main conduit provided with an opening intermediate its ends and an upwardly disposed discharge conduit; and a screw conveyer in said conduit loosely supported by its flights on the bottom of the main conduit, the flights of said screw intermediate of the rear end of the main conduit and the rearward wall of said discharge conduit being disposed in one direction, the flights of said screw intermediate the forward wall of said discharge conduit and the forward end of the main conduit being disposed in the opposite direction, while the flights of the screw at said discharge opening intermediate the planes of the forward and rear walls of the discharge conduit are disposed in the same direction as said first mentioned flights and oil"- set radially relative to the first two mentioned flights, all of said flights being in close juxtaposition to each other to maintain continuous movement of the fuel.

2. A conveyer comprising a horizontally disposed conduit provided in its top with a discharge opening intermediate of its ends and an upwardly disposed discharge riser; a yieldable closure member for the forward end of the conduit; and a screw conveyer extending continuously throughout said conduit, the flights of said screw intermediate of the receiving or rear end of the conduit and said discharge riser being disposed in one direction, the flights of the screw ill intermediate of said discharge riserand the forward end of the conduit being disposed in the reverse direction, while the flights of the screw intermediate of the adjacent ends of the first two mentioned flights are off-set radially relative to said first mentioned flights, all of said flights being contiguous and of substantially the same diameter.

3. A conveyer comprising a horizontally disposed conduit provided in its top and intermediate its ends with a discharge opening and an upwardly disposed riser; and a screw conveyer terminating forward of said riser, short of the outer forward end of the conduit and loosely supported by its flights on the bottom of the conduit, the flights of the screw rearward of said discharge opening and riser being single and disposed in one direction and becoming multiple adjacent the discharge opening, the flights of the screw forward of the discharge opening and riser being multiple and disposed in the opposite direction, while the single flight of the screw beneath said discharge opening extends substantially throughout the width of said opening and is disposed in the same direction as the first mentioned flights, all of the flights being arranged contiguous and substantially of equal diameter.

4. A conveyer comprising a horizontally disposed cylindrical conduit provided intermediate of its ends and in its upper side with a discharge riser of non-circular cross-section flaring toward its upper end in a lateral direction, the forward end of said conduit being provided with a yieldable closure member; regulable means for controlling said closure member; and a conveyor screw loosely mounted in said conduit and provided with two sections of forwardly feeding screw flights intermediate of the vertical plane of the forward wall of said riser and the rear end of the conduit and a section of reversely feeding flights intermediate of said plane and the forward end of the conduit, the section of said forwardly feeding flights disposed beneath the opening to the discharge riser extending from the vertical plane of the rear wall of the riser to the vertical plane of the forward wall of the riser and being ofl-set radially relative to the adjacent ends of the other two sections of flights with the ends of said section axially contiguous to the ends of th other mentioned flights.

WILLIAM O. MARTIN. 

